Hydraulic fracturing, commonly referred to as “fracing,” is a method of extracting hydrocarbons from a geological formation deep within the earth. The process entails a combination of drilling vertically and horizontally into the earth; introducing a mixture of water, a proppant (typically sand) to hold open the fractures, and optionally a chemical mixture to reduce equipment wear and to aid in the removal of the hydrocarbons; and building the pressure within the wellbore with the mixture until a sufficient pressure is achieved causing the formation to fracture, thus releasing the hydrocarbons which can be removed via the wellbore.
Water is an important element in the fracing process as it carries the proppant and chemicals deep into the earth. Thus the properties of the water, specifically temperature, can make a difference in overall fracing performance and efficiency. Achieving a proper water temperature may reduce the amount of chemicals needed and also decrease the amount of pressure on the pumps, pipes, and joints.
Heating the water generally involves pumping water into a heating vessel comprising a burner box, carrying the water through a coil (potentially 2″×1800′ in size) over an open flame, then introducing the heated water back into the fracing system. In order to heat this much water, upwards of 400 gallons per hour of propane or diesel fuel can be consumed. It also requires the added cost of fuel delivery and storage of flammable materials, and requires an open flame located near a mining system involving chemicals under pressure. Therefore, the art of fracing could benefit from a water heating system capable of more efficiently heating the water without use of an open flame.